While digital compact cameras have tended to record low-res video since they became popular a decade ago, tech boffins have long argued that it was impossible to have the same feature on a more advanced digital SLR camera – at least, not on an SLR in the conventional sense.

So the industry was surprised last year when Nikon introduced 1,280-x-720 pixel high-def video on its D90 digital SLR, in a sign of things to come. Now most major manufacturers offer a digital SLR or SLR-type camera with HD video capabilities.

Out of the major manufacturers, it’s surprizing that Sony is currently the only major player without a digital SLR offering HD video – despite the company’s rich heritage in the camcorder market. Of course, Sony lacks the decades of lens-making experience of the likes of Canon, Nikon and Pentax.

However, lenses are undoubtedly another advantage of shooting video on a digital SLR or interchangeable lens: you can choose from potentially hundreds, in Nikon’s case running from 10mm to 600mm. Which dedicated HD camcorder, professional or otherwise, can offer such scope?

So, taking into account sound (stereo or mono) and framerate (a higher number of frames per second – or ‘fps’ – theoretically giving you a smoother picture), we’ve looked at six contenders, comparing their HD video and of course – since there is much more to these products than simply video – how they perform as all-round digital SLRs.

While we wouldn’t claim that HD video alone is reason enough to choose one of our models, as an added extra it’s well worth having. With even our cheapest contender coming in at £600, none of the cameras we looked at here has serious failings in HD video – or, indeed, any other area.

When examined on individual merits, each presents a strong case – although if you already own lenses for a particular system, that will clearly influence which model you’d plump for.

So, with most of the models at pretty much level pegging, which is worth singling out for further investigation? Like its predecessor the G1, the innovative Panasonic Lumix GH1 impressed us with its smooth, sharply detailed performance against ‘proper’ digital SLRs from Canon, Nikon and Pentax. However, its high price leaves us wondering exactly who it’s aimed at.

Something for everybody

As the company’s most professional digital SLR to date and the only one to currently shoot video, Pentax's K-7 is a bargain in comparison with Canon’s 5D Mark II, and offers a more conventional alternative to the almost identically priced GH1. But if you don’t need a semi-professional model then the Olympus E-P1, Nikon D5000 or Canon EOS 500D offer better value.

If you’re looking for the cheapest route to better photographs – and Full HD video with stereo sound into the bargain – then the Olympus E-P1 is highly recommended. The fact that it omits flash and a viewfinder is a little odd, though.

That leaves age-old rivals from Canon in the Canon EOS 500D and Nikon’s confusingly similar-sounding Nikon D5000 to slug it out for supremacy. On paper the Canon should nail it, by virtue of 1,920-x-1,080 resolution to the Nikon’s 1,280-x-720 pixels, but in reality we preferred the more ‘filmic’ quality of the Nikon’s clips. Factor in the fact that, for the price of the Canon, we can buy the Nikon body plus a Vibration Reduction lens and still have £70 change (enough to buy a round of drinks for extras in our first video project, handily), and the Nikon D5000 takes our top honours this time around for an HD video-sporting digital SLR.